This invention relates to an improved transfer system for transferring a patient from a hospital chair or stretcher, for example, into or out of a tub enclosure. More specifically, this invention relates to the lift mechanism associated with such a transfer system.
Vanderheiden in application Ser. No. 07/489,489 now abandoned discloses a patient transfer system which includes a lift mechanism for transporting a hospital patient chair into or out of a tub enclosure. The lift system may be incorporated with the frame for the tub enclosure. Alternatively, the lift mechanism may be associated with the frame of a mobile patient carrier. In each system environment, the lift mechanism includes hollow, concentric, telescoping tubes or posts with a block support at the top end of the inner tube for cooperatively engaging and supporting a patient chair. The inner tube thus supports the patient chair and may be telescoped or raised to thereby raise the patient chair over the edge of a tub and then lower the chair and patient into the tub.
The inner tube or post is moved up and down or telescopes within the fixed outer tube or post by means of a screw actuator. The connection of the screw actuator to the inner tube and the arrangement of bushings between the inner and outer tubes, though workable in the mechanism of the type disclosed by Vanderheiden presents some difficulties, for example, during repair or assembly of the lift mechanism. This results in higher expense for repair and replacement of worn parts, and with respect to lubricating and servicing the mechanism. Thus, there is a need for an improved coupling construction for attaching the screw actuator for the lift mechanism to the telescoping inner tube and for positioning the telescoping inner tube slidably within the fixed outer tube.